When people think about physics, several things tend to come to mind, especially if they have never studied the subject. One thing that tends to come to mind is force, as do often  energy and power.  Names like Newton and Einstein also tend to be brought up. We have spent a fair amount of time so far in this course, doing lots of problems, but we have yet to mention any of these items! This is about to change....

Isaac Newton (1642 - 1727) is considered to  be one of the greatest scientists of all time. When he was still a young man, he invented the calculus, and over a period of about 20 years he developed what are now known as Newton’s three laws of motion, along with the Universal Law of Gravitation.  He also realized that sunlight is really composed of pure colors, and dabbled in chemistry and alchemy.

In this lecture, we will be introduced to Newton’s three laws of motion, and will start seeing how they can be applied to solving basic force problems. In the following two lectures, we will be adding new forces to our force-toolbox, which will allow us to tackle more and more realistic problems. Finally, Lecture 11 will apply all of our understanding of forces and motion to the straightforward, but often counterintuitive study of circular motion.

At the root of Newton’s laws is, of course, the concept of force.  We may think of a force as that which causes an object’s motion to change — that is, a force is that which causes an object to accelerate.  We will see the intimate  relation between force and acceleration in Newton’s second law.

Now, without further ado, we proceed to our discussion of Newton’s three laws.